i would like to know what is the thermal resistance Rjc for a package LQFP-64. I didn't saw the value in the datasheet and i need it to know the Tj temperature, when PDmax is 0.1mW and my case is 90degrees.
ST spreads or hides chip temperature data in many documents, it is difficult to find exact figures. But I would quess that the temperature is very close to the external temp. 0.1mW is a very small power. For a 746 chip LQFP100 it was 43 degrees per watt.
ST spreads or hides chip temperature data in many documents, it is difficult to find exact figures
I didn't find it particularly difficult to find; it's simply in the DS for the given model. Not that surprisingly, it's (slightly) dependent on particularities of each chip, not just the package itself. Two randomly selected examples:
For critical commercial designs I'd strongly recommend working with an FAE who can get the answers, test data and characterization needed.
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